I have R10 here... R10 sounds incredibly good with a headphone with 1/4 inch jack. It sounds just incredible... It sounds better than sound from my PC or laptop. The only thing that will rival this would be a great desktop USB headphone amplifier.

I have both. To me R10 sounds more realistic, and quite detailed. The amp section is done very well also. X5 is probably the best around it's price range as I prefer it over the DX90. X5's amp section is better than DX90 amp section IMO. X5 is quite detailed also with good clarity, but R10 has that and it sounds more realistic. I can describe X5 as clean and clear sounding(you sense that as it shoots the details at you, and the details have a refined sound or clarity), and R10 as detailed and real. Although less real, X5 has a quite interesting sound as it sounds like there is imaging to the sound or definition that stands out. I think X5's signature is fun because of the clarity that stands out and pseudo imaging. R10 vocals is euphoric and very realistic. R10's ui is slower and not as responsive as the X5, R10 takes time to scan files, and there is a delay when you change tracks. X5 is better in this regard, and of course the size.

Blast, looks like my X5 has just died. Hadn't used for a few days, then cut off mid-way through a song even though battery showed full. Put on charge, hoping I'd mis-read it, but still wouldn't come on. After 30 minutes charging, or at least with red light on, I tried and was relieved it started. Taken off charge as went green, fully charged and nothing, wont start up again.

Blast, looks like my X5 has just died. Hadn't used for a few days, then cut off mid-way through a song even though battery showed full. Put on charge, hoping I'd mis-read it, but still wouldn't come on. After 30 minutes charging, or at least with red light on, I tried and was relieved it started. Taken off charge as went green, fully charged and nothing, wont start up again.

Blast, looks like my X5 has just died. Hadn't used for a few days, then cut off mid-way through a song even though battery showed full. Put on charge, hoping I'd mis-read it, but still wouldn't come on. After 30 minutes charging, or at least with red light on, I tried and was relieved it started. Taken off charge as went green, fully charged and nothing, wont start up again.

Is there anything I can do before contacting supplier?

Try removing the cards and resetting the device. I don't know why this works, but it happened to me the other day at the end of a track and this fixed it with no problems since.

Can anyone tell me if there's a bugzilla or anything from FiiO about the fact (as of v2.0) that you can't boot the E5 while it's plugged into a charger?
Having to unplug the charger just to wake it up then plugging it straight back in is... getting old. More to the point it's sure to wear down/damage the socket eventually. Thanks.

On older firmware pressing the OK button woke up the player from charging mode but I thought this has been changed to the power button as of FW2.0?